ZIRCONIA VERSUS PFMs: WHICH SHOULD YOU CROWN THE WINNER?

Patients with Dental issues often end up confused about what kind of restorative material to go with - given there is a sea of options to choose from. The world of dental research and research on the various dental materials has evolved so much in the recent past. Today, there are so many materials to choose from unlike a few decades ago when metal crowns or porcelain crowns were the only options. There is a variety of dental material that has come up in recent years such as Composite Resin crowns, PFM or Porcelain fused to metal crowns, Ceramic crowns, All Ceramic crowns and the newer variant - Zirconia Crowns. All of these crowns have their own advantages and a small list of disadvantages as well.&

Although the two major types of crowns remain Metal and Porcelain or Ceramic today, there are many varieties of the same that have come up in the recent past. One of the notable types of dental restoration material in this regard is the Porcelain Fused to Metal. Remaining relevant throughout the various changes that have happened in the dental industry, Porcelain Fused to Metal is still a commonly used crown in many specific case scenarios. Closest to the metal crown in strength and durability and providing the esthetics of Porcelain and Ceramic Crowns, Porcelain Fused to Metal crowns is one of the few crowns that has stood the test of time.

Dental Crowns and Dental Materials

1. Position of Crown

There are two different kinds of crown material that are suggested based on where the crown is placed - for anterior crowns a more aesthetically pleasing crown which does not give away the use of crown is preferred. For posterior crowns, a highly durable and strong crown is to be recommended. Therefore the position of the crown is important for the selection of the dental material. Anterior crowns are preferred in esthetically pleasing shades whereas posterior crowns need to have a high flexural strength along with a higher threshold for bite force.

2. Patient Characteristics

The patient may have some unique habits and characteristics such as Bruxism where the patient grinds their teeth in the night. Some patients may have metal allergies which eliminates the usage of metal based crowns. Some patients may have low accessibility or low co-operation when it comes to dental care and for such patients, a durable low maintenance crown needs to be prescribed.

3. Dental Hygiene

Dental hygiene is especially important for the health and durability of the crown. Patients who have low dental hygiene such as young children or older adults or those who have low access to dental healthcare need a strong and durable dental crown that needs low maintenance. Choosing a crown that is esthetically pleasing often comes with high maintenance leaving only metal based crowns as an option.

4. Cost of the Crown

Economic affordability is one of the most important things for dental procedures as not all medical insurances cover dental procedures. Patients who cannot afford to have premium dental material based crowns need more economic options that they can choose from. Esthetically pleasing crowns come with a cost and therefore a variety of hybrid options have come up that combine esthetics with functionality and with a reduction in cost.

5. Dental Procedure Followed

Sometimes the type of dental procedure that has been followed is important in the selection of the dental material that is chosen. If a major portion of the tooth has been removed, then a dental material that has the need for more space and contouring cannot be considered. Ceramic based crowns have a thicker structure and when there is not enough original tooth structure to support, the restoration may not have the required strength.

Porcelain Fused to Metal Crowns

Porcelain Fused to Metal Crowns is a perfect hybrid of Metal crowns and porcelain crowns. The dental material combines the strength of the metal crown with a metal substructure in the core along with a porcelain exterior that fulfils the need for aesthetics in patients. Because of the need for a teeth like exterior structure in both posterior as well as in anterior restorations, PFM or Porcelain Fused Metal Crowns were invented by dental researchers. It has been in use for a long time, ever since the 1950’s perhaps and is still a relevant restoration material in the dentistry world.

When it comes to the alloy of choice, patients can choose from 3 categories:

1. Non-Precious

Non-precious metals are base metals that include metals such as Nickel, Chromium, Beryllium or Cobalt. These metals are often found in combination with Noble metals as well but the strength of the metal composition is less than 25% in Non-precious crowns. These crowns are more affordable and offer a good alternative to metal crowns or pure porcelain crowns.

2. Semi-Precious

Semi-precious metals have a noble metal content of 25% on average or slightly more - and includes the likes of Gold, Platinum or Palladium. These crowns offer better strength and durability than Non-precious crowns. They are slightly more expensive than Non-precious crowns.

3. High Noble

High Noble metals include 40% and more of the noble metal of choice. Mostly, Gold is used for these types of restorations with about 40% strength in the overall composition. The rest of the structure is layered with Feldspathic porcelain.

There are many advantages and a few disadvantages of PFM crowns just like any other dental crowns that have existed. Like the name suggests, the metal substructure within offers strength and durability of metal but also comes with the greyish metal shadow and the margin around the crown which can become unpleasant to look at. Even though Porcelain offers a good cover and provides a teeth like appearance from the outside, from closer observation, it does look artificial. Porcelain is also not famously popular for its chipping tendency and the ability to cause wear in the opposing teeth.

Below are some of these points in comparison with each other: